1. Field of the Invention
The present invention relates to an ink supply system and an inkjet printer.
2. Description of the Related Art
There are conventional inkjet printers using additional ink tanks, in addition to ink cartridges that supply ink to ink heads for discharging ink, in order to increase the amount of ink available (see, for example, Japanese Laid-Open Patent Publication No. 2010-94847).
With inkjet printers of this type, an ink head and an ink cartridge are connected together via a main supply channel. Another ink tank is connected to a middle portion of the main supply channel via a sub-supply channel. A solenoid valve is provided at a downstream portion of the main supply channel. When printing, the solenoid valve is opened so that ink stored in the ink cartridge and/or the other ink tank is supplied to the ink head. During standby, the solenoid valve is closed so that ink stored in the ink cartridge and the other ink tank is not supplied to the ink head.
With the inkjet printer described above, however, the solenoid valve is closed during standby. Therefore, when the temperature around the inkjet printer increases, ink in a section of the main supply channel between the solenoid valve and the ink head may possibly swell. During standby, ink in a section of the main supply channel between the solenoid valve and the ink head may possibly swell, resulting in ink leakage from the ink head.